The present invention generally relates to recording of information on a recording sheet and more particularly to the art of ink-jet recording in which visual recording of an image is made on a recording paper by impinging ink droplets thereon.
In the art of ink-jet recording, in which recording of image is made by impinging color ink droplets on a recording paper in response to an image signal, it is important to avoid spreading of the ink on the recording paper. While the problem of spreading of the ink on the recording paper is controlled satisfactorily when a specially produced recording paper is used at the time of ink-jet recording, the problem appears more or less conspicuously when an ordinary recording paper, including those used commonly for xerographic recording of images, is used for the recording medium of the ink-jet recording process.
In order to suppress the foregoing problem of spreading of ink on the recording paper at the time of ink-jet recording, it is proposed to record an ink image once on an intermediate recording medium and then transfer the ink image thus formed to an ordinary recording paper, as disclosed in the Japanese Laid-Open Patent Publication 7-89067. In such a process, it is expected that the ink on the intermediate recording medium increases the viscosity due to the evaporation of the solvent in the ink while the ink is still on the intermediate recording medium.
Unfortunately, this conventional process is inherently ineffective for avoiding the problem of spreading of ink due to the fundamental nature of ink-jet recording, which relies upon the use of an ink containing little resin or solid component. It should be noted that the use of a resin component or solid component in the ink would inevitably invite the problem of clogging of the ink-jet nozzle. Further, the foregoing conventional process has a tendency of incomplete image transfer, and associated therewith, there arises a need of cleaning the intermediate medium each time the intermediate ink image is transferred, for removing the remaining ink from the intermediate medium. Further, the intermediate medium tends to collect particles of the recording paper, while the particles thus collected tend to cause the problem of clogging of the ink-jet nozzle.
Further, there is an ink-jet process, as disclosed in the Japanese Laid-Open Patent Publication 6-92009, which avoids the spreading of ink on the recording paper by projecting a curing agent substantially simultaneously to the ink droplets on the recording paper, such that a droplet of the curing agent hits the portion of the recording paper to which an ink droplet from the ink-jet nozzle is directed. Thereby, the curing agent causes a curing of the ink droplet.
This process, while being able to eliminate the problem of spreading of the ink on the recording paper, has a drawback in that it requires an additional nozzle for projecting the curing agent in alignment with the ink droplets, and the cost of the ink-jet recording is inevitably increased. Further, the foregoing process of using a curing agent generally requires time for the ink to be cured, and the speed of the image recording is inevitably slowed down.
Further, there is an ink-jet process that avoids the spreading of ink on the recording paper as disclosed in the Japanese Laid-Open Patent Publication 5-96720, by uniformly applying an agent on the surface of the recording paper prior to the ink-jet recording, such that the ink droplets landed on the recording paper experience a curing or fixing as a result of contact with the curing agent.
While this process is effective for avoiding the spreading of ink image on the recording paper, the process has a drawback in that the curing agent, being a substance soluble to water or oil, tends to react with the solvent of the ink and the recorded image may be degraded as a result of such a reaction. In other words, the image recorded on the recording paper according to such a process is not stable and may be degraded with time.